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Message-ID: <1a26d7b3-1020-50c5-f0a3-ebc645cdcddf@redhat.com>
Date:   Tue, 18 Jan 2022 11:07:36 +0800
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Subject: Re: [RFC 2/3] vdpa: support exposing the count of vqs to userspace
Content-Language: en-US
To:     "Longpeng(Mike)" <longpeng2@huawei.com>, mst@redhat.com,
        sgarzare@redhat.com, stefanha@redhat.com
Cc:     virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        arei.gonglei@huawei.com, yechuan@huawei.com,
        huangzhichao@huawei.com
References: <20220117092921.1573-1-longpeng2@huawei.com>
 <20220117092921.1573-3-longpeng2@huawei.com>
From:   Jason Wang <jasowang@redhat.com>
In-Reply-To: <20220117092921.1573-3-longpeng2@huawei.com>
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在 2022/1/17 下午5:29, Longpeng(Mike) 写道:
> From: Longpeng <longpeng2@huawei.com>
>
> - GET_VQS_COUNT: the count of virtqueues that exposed
>
> Signed-off-by: Longpeng <longpeng2@huawei.com>
> ---
>   drivers/vhost/vdpa.c       | 13 +++++++++++++
>   include/uapi/linux/vhost.h |  3 +++
>   2 files changed, 16 insertions(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 1eea14a4ea56..c1074278fc6b 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -369,6 +369,16 @@ static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp)
>   	return 0;
>   }
>   
> +static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
> +{
> +	struct vdpa_device *vdpa = v->vdpa;


While at it, I think it's better to change vdpa->nvqs to use u32?

Thanks


> +
> +	if (copy_to_user(argp, &vdpa->nvqs, sizeof(vdpa->nvqs)))
> +		return -EFAULT;
> +
> +	return 0;
> +}
> +
>   static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>   				   void __user *argp)
>   {
> @@ -509,6 +519,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
>   	case VHOST_VDPA_GET_CONFIG_SIZE:
>   		r = vhost_vdpa_get_config_size(v, argp);
>   		break;
> +	case VHOST_VDPA_GET_VQS_COUNT:
> +		r = vhost_vdpa_get_vqs_count(v, argp);
> +		break;
>   	default:
>   		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
>   		if (r == -ENOIOCTLCMD)
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index bc74e95a273a..5d99e7c242a2 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -154,4 +154,7 @@
>   /* Get the config size */
>   #define VHOST_VDPA_GET_CONFIG_SIZE	_IOR(VHOST_VIRTIO, 0x79, __u32)
>   
> +/* Get the count of all virtqueues */
> +#define VHOST_VDPA_GET_VQS_COUNT	_IOR(VHOST_VIRTIO, 0x80, __u32)
> +
>   #endif